Hearing aid comprising slot antenna

Abstract

A behind-the-ear type hearing aid (10) is provided. The hearing aid (10) comprises: a housing (12) adapted to be worn behind an ear of a user; a microphone (14) arranged in the housing (12) and configured to receive sound; a processing circuit (16) arranged in the housing (12) and configured to convert the received sound into a hearing loss compensated signal; a receiver (18) arranged outside of the housing (12), in or near an ear canal of the user, the receiver (18) being configured to receive the hearing loss compensated signal and output said signal as audio; and a slot antenna (20) arranged in the housing (12), the slot antenna (20) comprising: an antenna plane (22) extending in a plane with a normal direction being between 45°-135° to an ear-to-ear axis of the user when the hearing aid (10) is worn; and a slot (24) in the antenna plane (22) shaped as a loop. A method (100) for manufacturing such a hearing aid is further provided.

Description

[0001] HEARING AID COMPRISING SLOT ANTENNA

[0002] Technical Field

[0003] The present inventive concept relates to a hearing aid comprising a slot antenna. In particular, the present inventive concept relates to a hearing aid comprising a loopshaped slot antenna arranged perpendicular to a head of a user when being worn.

[0004] Background

[0005] Modem hearing aids comprise several antennas, such as antennas for connecting to each other and to a personal device of a user. The personal device may e.g. be a smart phone or computer. The connection between the personal device and the hearing aid may e.g. be Bluetooth®, Wi-Fi or other suitable fast, low energy alternatives.

[0006] Modem hearing aids are also relatively small, so fitting the antennas into the hearing aid while ensuring a good transmission is a constant struggle when designing hearing aids. It would hence be beneficial to have access to antennas that are robust and flexible in their placement and transmission characteristics.

[0007] It is thereby an object of the present inventive concept to improve the antenna performance of such hearing aids. In particular, an object of the present inventive concept is to provide an efficient antenna that may be arranged in novel and efficient positions. This and other objects are achieved by the features set out in the appended independent claims, with embodiments set out in the dependent claims.

[0008] Accordingly, a first aspect of the inventive concept is provided by a behind- the-ear type hearing aid system. The hearing aid system comprises: a housing adapted to be worn behind an ear of a user; a microphone arranged in the housing and configured to receive sound; a processing circuit arranged in the housing and configured to convert the received sound into a hearing loss compensated signal; a receiver arranged outside of the housing, in or near an ear canal of the user, the receiver being configured to receive the hearing loss compensated signal and output said signal as audio; and a slot antenna arranged in the housing. The slot antenna comprises: an antenna plane extending in a plane with a normal direction being between 45°-135° to an ear-to-ear axis of the user when the hearing aid is worn; and a slot in the antenna plane shaped as a loop.

[0009] The slot antenna is a robust antenna type that is easy to fit in different locations in the hearing aid.

[0010] By arranging the slot antenna in a plane with a normal direction being between 45°-135° to an ear-to-ear axis of the user, the transmission characteristics of the antenna is optimized. This is because radiation from the antenna is easily directed away from the head of the user and towards e.g. a front pocket of the user, which may contain a smart phone. Furthermore, there may be less negative impact caused by ear material when using such an arrangement.

[0011] This placement is far away from the ear of the user in conventional behind- the-ear hearing aids, thus reducing negative impact from the ear. Such a placement is further less affected by an ear shape of the user, so the antenna will perform similarly for many different users.

[0012] The antenna plane may e.g. be a metallic plate.

[0013] The slot in the antenna plane may be a narrow opening, e.g. in the metallic plate forming the antenna plane.

[0014] The antenna plane may be parallel to a ground plane.

[0015] Such an arrangement is space efficient and provides good transmission characteristics.

[0016] The ground plane may be part of a printed circuit board.

[0017] The components of the slot antenna may be easily integrated with components of the hearing aid, such as the ground plane being part of a printed circuit board. This facilitates a smaller footprint of the antenna, which leaves more room for other components of the hearing aid or simply smaller hearing aids.

[0018] The slot may comprise a set of load components distributed across the slot.

[0019] Such load components may be used to further direct and fine-tune the radiation of the slot antenna in a simple and affordable manner.

[0020] The set of load components may comprise at least one capacitor or inductor.

[0021] Such load components are cheap and efficient.

[0022] The set of load components may comprise at least one varactor diode.

[0023] Varactor diodes may be controlled by a feed voltage to provide different electrical characteristics. This may be used to manipulate the polarization and directivity of the slot antenna via a feed voltage controlled by a processor of the hearing aid. This would enable a user or hearing care professional to fine-tune the transmission-characteristics of the slot antenna once the hearing aid is fitted and used by a user, taking into account their experience using the hearing aid.

[0024] The set of load components may comprise at least three components.

[0025] Three components enable better control over the directivity of the radiation of the slot antenna.

[0026] The set of load components may be configured to adapt the polarization of the antenna radiation.

[0027] While the antenna is manufactured to provide certain transmission characteristics such as polarization and directivity, it may be difficult to achieve consistent results. As such, being able to configure the set of load components may ensure consistency without replacing the whole antenna.

[0028] The set of load components may be configured to enable an axial ratio of the polarization of the antenna to be 10 or lower in a direction where a directivity of the antenna is above 0.1 .

[0029] Such a polarization enables a reliable connectivity in directions that are relevant for the hearing aid, such as towards the other hearing aid or towards a smart phone.

[0030] The antenna plane may extend in a plane being substantially parallel with the ear-to-ear axis of the user when the hearing aid is worn.

[0031] By being parallel with the ear-to-ear axis of the user, the radiation of the antenna is stronger in directions away from the ear-to-ear axis, such as towards pockets of the user.

[0032] The antenna may be placed at a top section of the hearing aid with the antenna plane substantially horizontal when worn.

[0033] This placement is as far away from the ear of the user in conventional behind- the-ear hearing aids, thus reducing interference from the ear. Such a placement is further less affected by an ear shape of the user, so the antenna will perform similarly for many different users.

[0034] The antenna plane of the slot antenna may further comprise the microphone of the hearing aid arranged within a loop area enclosed by the slot in the antenna plane shaped as a loop. Such an arrangement is highly space-efficient and makes use of the fact that the antenna plane of the slot antenna is conductive.

[0035] According to a second aspect of the present inventive concept, a method for manufacturing a behind-the-ear type hearing aid is provided. The method comprises steps of: providing a housing adapted to be worn behind an ear of a user; providing a microphone arranged in the housing and configured to receive sound; providing a processing circuit arranged in the housing and configured to convert the received sound into a hearing loss compensated signal; providing a receiver arranged outside of the housing in or near an ear canal of the user, the receiver being configured to receive the hearing loss compensated signal and output said signal as audio; and providing a slot antenna arranged in or abutting the housing.

[0036] Providing the slot antenna comprises: providing an antenna plane extending in a plane being substantially parallel with an ear-to-ear axis of the user when the hearing aid is worn; and forming a slot in the antenna plane shaped as a loop.

[0037] This aspect may have all different embodiments and advantages of the first aspect of the present inventive concept.

[0038] The step of providing the slot antenna may further comprise: arranging a set of load components distributed along the slot in the antenna plane shaped as a loop; and adapting said set of load components to configure the polarization of the antenna radiation.

[0039] Such load components may be used to further direct and fine-tune the radiation of the slot antenna in an effective manner.

[0040] According to a third aspect of the present inventive concept, a hearing aid is provided. The hearing aid comprises: a housing; a microphone arranged in the housing and configured to receive sound; a processing circuit arranged in the housing and configured to convert the received sound into a hearing loss compensated signal; a receiver arranged in or near an ear canal of the user, the receiver being configured to receive the hearing loss compensated signal and output said signal as audio; and a slot antenna arranged in the housing.

[0041] The slot antenna comprises: an antenna plane; a slot in the antenna plane shaped as a loop; and a set of load components distributed along the loop of the slot; wherein said set of load components comprises at least one varactor diode arranged across the slot in the antenna plane and being fed a variable voltage. This aspect may have all different embodiments and advantages of the first aspect of the present inventive concept.

[0042] The processing circuit may be further configured to manipulate a variable voltage being fed to said at least one varactor diode to fine-tune transmissioncharacteristics of the slot antenna once in use.

[0043] Said at least one varactor diode being fed a variable voltage enables manipulation of input impedance, polarization and directivity of the slot antenna via a feed voltage controlled by a processor of the hearing aid. This would enable a user or hearing care professional to fine-tune the transmission-characteristics of the slot antenna once the hearing aid is fitted and used by a user, taking into account their experience using the hearing aid.

[0044] Description of drawings

[0045] The invention will be described in further detail with reference to preferred aspects and the accompanying drawing, in which:

[0046] Fig. 1a shows a schematic view of a slot antenna according to an embodiment;

[0047] Fig. 1 b shows a schematic view of a slot antenna according to an embodiment;

[0048] Fig. 2a shows a schematic view of a hearing aid according to an embodiment;

[0049] Fig. 2b shows a schematic view of a hearing aid according to an embodiment; and

[0050] Fig. 3 shows a flowchart of a method for manufacturing a hearing aid according to an embodiment.

[0051] Description of embodiments

[0052] In the following, terms such as a / an / the and comprising are intended to be interpreted as non-limiting. Any processor or computing unit may be implemented as an electronic circuit and electronic connections may be wired or wireless unless otherwise explicitly stated. Unless explicitly specified, a wireless connection may be implemented in any number of standards known to a person skilled in the art, such as Wi-Fi, Bluetooth®, Zigbee, 4G / LTE, 5G and so one.

[0053] Fig. 1a shows an embodiment of a slot antenna 20 adapted for being comprised in a behind-the-ear type hearing aid. The antenna 20 comprises an antenna plane 22 being a metallic plate and a slot 24 being a narrow opening in the antenna plane 22 shaped as a loop.

[0054] The antenna plane 22 is shown being in-plane of the figure, however when in use the antenna plane 22 extends in a plane with a normal direction being between 45°-135° to an ear-to-ear axis of a user when a hearing aid is worn.

[0055] The loop is rectangular in Figs. 1a-b, however other shapes such as an ellipsoid, circle or any other enclosing shape are possible.

[0056] In the embodiment of Fig. 1a, the slot 24 comprises a set of load components 28 distributed across the slot 24 shown as '+’ in Fig. 1a.

[0057] The set of load components 28 may comprise at least one capacitor, inductor and / or varactor diode.

[0058] In the embodiment of Fig. 1a, the slot 24 comprises a set of eight load components 28, however any number is possible. By comprising at least three load components 28, radiation characteristics of the antenna 20 may be controlled well after being manufactured.

[0059] The load components 28 tune the antenna 20 so that less power is reflected back and more is transmitted, to increase the efficiency of the antenna 20. Preferably at least 90 % of the power is transmitted.

[0060] For example, if output impedance is 50 Ohm, the antenna’s 20 input impedance should be the same, and this is fine-tuned by load components 28. More load components 28 gives a higher degree of freedom when doing this.

[0061] The set of load components 28 may further be configured to adapt a polarization of antenna radiation.

[0062] For example, circular polarization has better performance on body due to a higher bandwidth and robustness. This is difficult to achieve in practise, but an elliptical polarization relatively close to circular may be easier to achieve using load components 28 to fine-tune the polarization after manufacturing.

[0063] Polarization may differ depending on where it is measured, and the antenna 20 will be configured to have some amount of directivity towards useful directions, and away from the head of the user.

[0064] The set of load components 28 may be configured to enable an axial ratio of the polarization of the antenna 20 to be ten or lower, or preferably 5 or lower, or even more preferably 2 or lower, in a direction where a directivity of the antenna 20 is above 0.1. The directivity of the antenna 20 may be between 0.1-5.

[0065] Fig. 1 b shows another embodiment of a slot antenna 20 similar to the one in Fig. 1a. In Fig. 1 b, the antenna plane 22 is parallel to a ground plane 26. The ground plane 26 may be part of a printed circuit board of e.g. a hearing aid that will be discussed further in relation to Figs. 2a-b.

[0066] The antenna plane 22 of the slot antenna 20 further comprises components of the hearing aid, such as a microphone 14, arranged within a loop area enclosed by the slot 24 in the antenna plane 22 shaped as a loop. The microphone 14 is thereby arranged inside the metallic plate.

[0067] Fig. 1 b further shows a battery 15 of the hearing aid that may be used to power components of the hearing aid such as the microphone 14.

[0068] Fig. 1 b further shows a processing circuit 16 of the hearing aid that may be used to control the antenna 20 and / or components of the hearing aid such as the microphone 14.

[0069] The processing circuit 16 may cause the antenna 20 to excite using power from the battery 15.

[0070] The embodiment in Fig. 1 b is very space-efficient compared to conventional antennas.

[0071] Fig. 2a shows an embodiment of a hearing aid 10. The hearing aid 10 comprises a housing 12 adapted to be worn behind an ear of a user. The housing 12 is configured to fit behind an ear of the user, the hearing aid 10 is a behind-the-ear type hearing aid 10.

[0072] The hearing aid 10 comprises a microphone arranged in the housing 12 and configured to receive sound, and a processing circuit 16 arranged in the housing 12 and configured to convert the received sound into a hearing loss compensated signal. This conversion occurs according to any number of processes known in the field of hearing aids.

[0073] The hearing aid 10 further comprises a receiver 18 arranged outside of the housing 12, in or near an ear canal of the user. The receiver 18 is configured to receive the hearing loss compensated signal and output said signal as audio. The receiver may be any speaker suitable for use in a hearing aid 10.

[0074] The hearing aid 10 further comprises a slot antenna 20 arranged in the housing 12 as described in relation to Figs. 1a-b. Fig. 2b shows an embodiment of a hearing aid 10 similar to the one in Fig. 2a. The hearing aid 10 is being worn by a user.

[0075] The hearing aid 10 comprises a slot antenna 20 arranged in the housing 12, the slot antenna 20 comprising: an antenna plane 22 extending in a plane with a normal direction being between around 45°-135°, such as between 60°-120° or 75° - 105°, to an ear-to-ear axis of the user when the hearing aid 10 is worn.

[0076] In Fig. 2b, the antenna plane 22 extends in a plane being substantially parallel with the ear-to-ear axis of the user when the hearing aid 10 is worn, i.e. the antenna plane 22 extends in a plane with a normal direction (shown with an arrow in Fig. 2b) being between around 90° to the ear-to-ear axis of the user when the hearing aid 10 is worn.

[0077] The antenna 20 is placed at a top section of the hearing aid 10 with the antenna plane 22 being substantially horizontal when worn.

[0078] The antenna 20 may in other embodiments be placed in a different section of the hearing aid 10, whereby the antenna plane 22 would follow the outer contour of the edge of the housing 12 of the behind-the-ear type hearing aid 10 and no longer be horizontal. This is shown e.g. in Fig. 2a.

[0079] Fig. 3 shows a flowchart of a method 100 for manufacturing a behind-the-ear type hearing aid, such as the hearing aid shown in Fig. 2a or Fig. 2b. The method steps S110-158 are shown sequentially, however several different sequences are possible within the scope of the appended claims.

[0080] The method steps S156-S158 shown with dashed lines are considered optional.

[0081] The method 100 comprises providing S110 a housing adapted to be worn behind an ear of a user. The housing may e.g. be injection moulded, pressed or 3D- printed and may be made of plastics and / or metals.

[0082] Next, the method 100 comprises providing S120 a microphone arranged in the housing and configured to receive sound. The microphone may e.g. be directional or binaural and there may be several microphones arranged in the housing.

[0083] Next, the method 100 comprises providing S130 a processing circuit arranged in the housing and configured to convert the received sound into a hearing loss compensated signal. The processing circuit may be any processor known in the art suitable for being arranged inside of a hearing aid and the configuration may be performed according to industry standards.

[0084] Next, the method 100 comprises providing S140 a receiver arranged outside of the housing in or near an ear canal of the user, the receiver being configured to receive the hearing loss compensated signal and output said signal as audio. The receiver is a speaker and may be receiving the hearing loss compensated signal through a wired or wireless connection with the processing circuit.

[0085] Next, the method 100 comprises providing S150 a slot antenna arranged in the housing. The slot antenna may be as discussed in relation to Figs. 1a-b.

[0086] Providing S150 the slot antenna comprises providing S152 an antenna plane extending in a plane being substantially parallel with an ear-to-ear axis of the user when the hearing aid is worn. The antenna plane may be arranged separate from and connected to the rest of the hearing aid or integrated with other components of the hearing aid.

[0087] Providing S150 the slot antenna further comprises forming S154 a slot in the antenna plane shaped as a loop. This slot may be formed prior to arranging the slot antenna in the housing and may have been formed by cutting out a slot in the antenna plane or by combining two antenna planes to form a slot between them. Cutting out a slot in the antenna plane may e.g. be done using a laser or mechanical press / knife.

[0088] Providing S150 the slot antenna may further comprise arranging S156 a set of load components distributed along the slot in the antenna plane shaped as a loop. This may be done prior to arranging the slot antenna in the housing.

[0089] Providing S150 the slot antenna may further comprise adapting S158 said set of load components to configure the polarization of the antenna radiation. This may be done prior to arranging the slot antenna in the housing and / or while the hearing aid is in use, depending on the load components.

[0090] The preceding description has been a non-exhaustive disclosure of different exemplifying embodiments of the present inventive concept. This is not to be misconstrued as limiting the scope of the protection sought for the inventive concept, which is defined by the appended claims.

Claims

CLAIMS1 . A behind-the-ear type hearing aid (10) comprising: a housing (12) adapted to be worn behind an ear of a user; a microphone (14) arranged in the housing (12) and configured to receive sound; a processing circuit (16) arranged in the housing (12) and configured to convert the received sound into a hearing loss compensated signal; a receiver (18) arranged outside of the housing (12), in or near an ear canal of the user, the receiver (18) being configured to receive the hearing loss compensated signal and output said signal as audio; and a slot antenna (20) arranged in the housing (12), the slot antenna (20) comprising: an antenna plane (22) extending in a plane with a normal direction being between 45°-135° to an ear-to-ear axis of the user when the hearing aid (10) is worn; and a slot (24) in the antenna plane (22) shaped as a loop.

2. The hearing aid (10) according to claim 1 , wherein the antenna plane (22) is parallel to a ground plane (26).

3. The hearing aid (10) according to claim 2, wherein the ground plane (26) is part of a printed circuit board.

4. The hearing aid (10) according to any one of the preceding claims, wherein the slot (24) comprises a set of load components (28) distributed across the slot (24).

5. The hearing aid (10) according to claim 4, wherein said set of load components (28) comprises at least one capacitor or inductor.

6. The hearing aid (10) according to claim 4 or 5, wherein said set of load components (28) comprises at least one varactor diode.

7. The hearing aid (10) according to any one of claims 4-6, wherein said set of load components (28) comprises at least three components.

8. The hearing aid (10) according to any one of claims 4-7, wherein said set of load components (28) is configured to adapt a polarization of antenna radiation.

9. The hearing aid (10) according to claim 8, wherein said set of load components (28) is configured to enable an axial ratio of the polarization of the antenna (20) to be 10 or lower in a direction where a directivity of the antenna (20) is above 0.1 . io10. The hearing aid (10) according to any one of the preceding claims, wherein the antenna plane (22) extends in a plane being substantially parallel with the ear-to-ear axis of the user when the hearing aid (10) is worn.11 . The hearing aid (10) according to any one of the preceding claims, wherein the antenna (20) is placed at a top section of the hearing aid (10) with the antenna plane (22) being substantially horizontal when worn.

12. The hearing aid (10) according to any one of the preceding claims, wherein the antenna plane (22) of the slot antenna (20) further comprises the microphone (14) of the hearing aid (10) arranged within a loop area enclosed by the slot (24) in the antenna plane (22) shaped as a loop.

13. A method (100) for manufacturing a behind-the-ear type hearing aid, the method (100) comprising steps of: providing (S110) a housing adapted to be worn behind an ear of a user; providing (S120) a microphone arranged in the housing and configured to receive sound; providing (S130) a processing circuit arranged in the housing and configured to convert the received sound into a hearing loss compensated signal; providing (S140) a receiver arranged outside of the housing in or near an ear canal of the user, the receiver being configured to receive the hearing loss compensated signal and output said signal as audio; and providing (S150) a slot antenna arranged in the housing, wherein providing the slot antenna comprising: providing (S152) an antenna plane extending in a plane being substantially parallel with an ear-to-ear axis of the user when the hearing aid is worn; and forming (S154) a slot in the antenna plane shaped as a loop.

14. The method according to claim 13, wherein the step of providing (S150) a slot antenna further comprises: arranging (S156) a set of load components distributed along the slot in the antenna plane shaped as a loop; and adapting (S158) said set of load components to configure the polarization of the antenna radiation.

15. A hearing aid (10) comprising: a housing (12); a microphone (14) arranged in the housing (12) and configured to receive sound; a processing circuit (16) arranged in the housing (12) and configured to convert the received sound into a hearing loss compensated signal;a receiver (18) arranged in or near an ear canal of a user, the receiver (18) being configured to receive the hearing loss compensated signal and output said signal as audio; and a slot antenna (20) arranged in the housing (12), the slot antenna (20) comprising: an antenna plane (22); a slot (24) in the antenna plane shaped as a loop; and a set of load components (28) distributed across the slot (24); wherein said set of load components (28) comprises at least one varactor diode arranged across the slot (24) in the antenna plane (22) and being fed a variable voltage.

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